Method of state decomposition and slice composition on elliptical delamination in composite laminate

The transverse loading state of a laminate with elliptical delamination is decomposed by means of the principle of superposition, so the problem of delamination can be reduced to the analysis problem of the additional displacements and stresses caused by the additional shear loading acting on the delamination surface, and thus a simple mechanics model of the delamination area is established. The laminate sections parallel to the coordinate planes can be regarded as laminated beams with delamination, the displacements of which can be expressed by the analytical solutions of the additional displacements in the above beams. In this way, the additional displacement field satisfying the displacement boundary condition of the delamination area can be established. Finally, a closed form solution of additional displacements is obtained by the principle of minimum potential energy. The above results are compared with the convergent solutions obtained by the method of trigonometric series. It shows that the deflections acquired from two different ways agree with each other very well and are greater than that in plane displacements by 1-2 order of magnitude.